diff --git a/library/bignum_core.c b/library/bignum_core.c
index a3547bd..ad22a15 100644
--- a/library/bignum_core.c
+++ b/library/bignum_core.c
@@ -516,8 +516,6 @@
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
-    if ( X == NULL || N == NULL ) goto cleanup;
-
     MBEDTLS_MPI_CHK( mbedtls_mpi_lset( X, 1 ) );
     MBEDTLS_MPI_CHK( mbedtls_mpi_shift_l( X, N->n * 2 * biL ) );
     MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( X, X, N ) );
diff --git a/library/bignum_core.h b/library/bignum_core.h
index d46aea3..9870da4 100644
--- a/library/bignum_core.h
+++ b/library/bignum_core.h
@@ -426,8 +426,7 @@
  *                to store the value of Montgomery constant squared.
  * \return        #MBEDTLS_ERR_MPI_DIVISION_BY_ZERO if \p N modulus is zero.
  * \return        #MBEDTLS_ERR_MPI_NEGATIVE_VALUE if \p N modulus is negative.
- * \return        #MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED \p N, \p X are NULL
- *                or other operations fail.
+ * \return        #MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED if other operations fail.
  */
 int mbedtls_mpi_core_get_mont_R2_unsafe( mbedtls_mpi *X,
                                          mbedtls_mpi const *N );